Convert Rankine to Celsius
Convert Rankine to Celsius for clear metric reporting. Use (°R − 491.67) × 5/9.
How to Convert Rankine to Celsius
To convert Rankine to Celsius, subtract 491.67 and multiply by 5/9.
Conversion Formula:
(value - 491.67) * 5/9Understanding the Conversion
Rankine to Celsius is essential when engineering data or thermodynamic charts expressed in Rankine need to be communicated in everyday metric terms. Rankine degrees match Fahrenheit size but begin at absolute zero, so you must reverse both the offset and scaling to reach Celsius.
The formula is °C = (°R − 491.67) × 5/9. Subtract 491.67 to remove the absolute Fahrenheit baseline, then multiply by 5/9 to convert the smaller Fahrenheit-sized degrees to Celsius degrees. For example, 491.67°R equals 0°C, 671.67°R equals 100°C, and 419.67°R equals −40°C.
Use this conversion for reporting steam table data, combustion calculations, or refrigeration models that provide Rankine results but require Celsius outputs for audiences, documentation, or compliance. The converter handles the arithmetic precisely so you can focus on analysis.
If you prefer a two-step method, first convert Rankine to Kelvin by multiplying by 5/9, then subtract 273.15 to reach Celsius. The formula above combines both steps efficiently.
Conversion Examples
Example: Convert 536.67°R to Celsius
- Step 1: 536.67 − 491.67 = 45.
- Step 2: 45 × 5/9 = 25.
- Step 3: Result is 25°C.
536.67°R = 25°C
Shows a comfortable room temperature expressed in Rankine converted to Celsius.
Example: Convert 671.67°R to Celsius
- Step 1: 671.67 − 491.67 = 180.
- Step 2: 180 × 5/9 = 100.
- Step 3: Result is 100°C.
671.67°R = 100°C
Represents boiling water at standard pressure in Celsius.
Example: Convert 419.67°R to Celsius
- Step 1: 419.67 − 491.67 = -72.
- Step 2: -72 × 5/9 = -40.
- Step 3: Result is -40°C.
419.67°R = -40°C
Shows how Rankine values can convert to negative Celsius temperatures.
Conversion Formula
Rankine is Fahrenheit-based and absolute. Subtracting 491.67 removes the absolute offset that corresponds to 0°C, and multiplying by 5/9 converts the smaller Fahrenheit-sized degrees to Celsius degrees.
Conversion Chart
| Rankine | Celsius |
|---|---|
| 400 | -51.48 |
| 419.67 | -40 |
| 460 | -17.59 |
| 491.67 | 0 |
| 520 | 15.37 |
| 536.67 | 25 |
| 560 | 37.04 |
| 600 | 60.93 |
| 671.67 | 100 |
| 720 | 126.48 |
Quick Conversion Tip
Convert Rankine to Kelvin by multiplying by 5/9, then subtract 273.15 to reach Celsius if you prefer a two-step path.
Unit Definitions
Rankine (°R)
Absolute temperature scale using Fahrenheit-sized degrees.
Subtract 459.67 to reach Fahrenheit, or multiply by 5/9 to reach Kelvin. To get Celsius, subtract 491.67 then multiply by 5/9.
Celsius (°C)
Metric temperature scale with 0°C at freezing and 100°C at boiling.
From Rankine, use (°R − 491.67) × 5/9. From Kelvin, subtract 273.15. From Fahrenheit, subtract 32 then multiply by 5/9.
Common Use Cases
- Translate Rankine-based engineering outputs to Celsius for reports.
- Communicate thermodynamic results to teams using metric units.
- Academic exercises converting absolute Fahrenheit readings to Celsius.
- Compliance or safety documents that require Celsius values.
- Cross-check steam table or enthalpy data given in Rankine.
Frequently Asked Questions
Why subtract 491.67 instead of 459.67?
459.67 converts Rankine to Fahrenheit. To reach Celsius directly, you subtract 491.67 (which equals 32 + 459.67) before scaling by 5/9.
Is Rankine commonly used today?
It is still used in some U.S. engineering contexts, but most scientific and international work prefers Kelvin and Celsius.
Can Rankine values be negative?
No. Rankine is absolute, so it starts at 0°R. After converting to Celsius, the result can be negative because Celsius is a relative scale.